In the related art, a technique of controlling position by performing filtering for an external vibration frequency using an adaptive digital filter has been proposed. For example, using an adaptive digital filter based on positional difference information of a head of a hard disk drive (HDD), a feedback control in which a position control of the head is performed by controlling a voice coil motor (VCM) is applied.
In the related art, a transfer function of the adaptive digital filter also includes a fixed filter coefficient regardless of a variation of the vibration frequency. In this case, it may be difficult to perform self-adaptation for a change of the external vibration frequency.